I firearm with a round in a chamber will, in a house fire, shoot that round with the same force as if you'd pulled the trigger. IMHO, if you have time to get to a gun which is not in your immediate possession, you have time to chamber a round.
Many moons ago, in the grip of an Alaskan winter, my mother decided to 'burn' some trash in our fireplace to get some wood started. Not knowing a couple of Air Force issued 45 shells had fallen into a bedroom trash can (spilled off the dresser?) she and my sister snuggled up to the warmth only to be rudely awakened by a couple of blasts.
Ashes-on-fire were quickly upon them. My question is: how lethal might the projectile have been, given that the casing was probably moving with the same speed in the opposite direction? [True Story]